Lubricants



. etc. engines.

Patented July 5, 1949 LUBRICANTS Herschel G. Smith, Wallingford, andTroy L. Cantrell Lansdowne, Pa., and John G. Peters, Audubon, N. Jasslgnors to Gulf Oil Corporation, Pittsburgh, Pa., a. corpoi-ationofkennesylvania I No Drawing.

This invention relates to an improved lubricent and particularly to amineral oil lubricating baseble'nded with an additive which will improvethe lubricating properties.

The development of new automotive and other types of power developingmachines of increased power output has led to the introduction ofbearing surfaces which are corroded by oxidation products formed in thelubricant. Also the other parts of such power developing machines arecorroded and rusted by products formed during use such as water andoxidation products of the lubricant. Thesedifliculties have beenovercome to a certain extent by adding substances to the lubricant whichreduce the corrosion, rusting and other tendencies.

This invention has for its object to provide an improved lubricantcomprising a mineral oil lubricating base uniformly blended with anadditive which will retard rust and corrosion when the lubricant is usedfor the lubrication of power developing machines such as automotive,marine, Another object is to provide an improved mineral oil lubricatingbase containing an additive which will markedly reduce the corrosion ofbearings of a power developing machine. Another object is to provide amineral oil lubricating base having improved oiliness and reducedfoaming characteristics. Other objects will appear hereinafter.

' These and other objects are accomplished by our invention whichincludes a compounded lubricant comprising a, mineral oil lubricatingbase uniformly blended with a product obtainedby reacting a mixture of ahigh molecular weight unsaturated fatty acid and a high molecular weightaliphatic alcohol with maleic acid or maleic anhydride and an olefinoxide or corresponding glycol followed by substantial neutralizationwith a primary aliphatic amine containing from 8 to 26 carbon atoms; Ithas been found that such a compounded lubricant has reduced tendency torust'or corrode themachine parts and at the same time has reducedtendency to. foam. It has also been found that the oilinessof themineral oil base is improved. It is well known that a good lubricantshould be-capable of adhering to the metal bearing surface under'highbearing pressures and such property is commonly referred to as oiliness.I

In the following description we have set forth Application January 15,1948,- Serial N0. 2,556 Y 1 Claims. (01. 252-34) several of thepreferred embodiments of our invention but it is to be understood thatthey. are given for the purpose of illustration andn'ot in limitationthereoi. l

The mixture of high molecular weight unsaturated fatty acid and highmolecular weight alcohol can be obtained from any desired source. Aconvenient method of preparation is to hydrolize an ester of the desiredacid and alcohol such as sperm oil, which is primarily composed of anester of oleic acid and cetyl alcohol. On the other hand, the individualcomponents of the mixture may be obtained from difierent sources such asby synthesis or by preparation from natural materials and the twocomponents mixed in the desired proportions. .By the term high molecularweight we intend to designate an unsaturated acid Ol' an alcohol having8 or more carbon atoms in the molecule. Examples of suitable unsaturatedhigh molecular weight fatty acids are oleic, geranic; linoleic anderucic, etc. acids examples, of suitable alcohols are dodecanol,dodecenol, and

.oleyl alcohols, etc. In the event an ester such as sperm oil ishydrolyzed to yield a mixture composed mainly of unsaturated carboxylicacids and fatty alcohols'of the sperm oil, the hydrolysis may be.accomplished in known manner, such as by saponiflcation with an alkalifollowed bynremoval of the alkali metal from the soaps by treatment withan acid, or by heating the sperm' oil in the presence of water and a fatsplitting agent such as sulfuric acid. I I

. Theproportion of high molecular weight alcohol to high molecularweight fatty acid may vary considerably. In general we prefer to usefrom about one-half mol to about 5-mols of alcohol per mol of acid.However, larger or smaller amounts may be used. Sperm oils usuallycontain from about 45 to about mol per cent. of alcohol based on thetotal amount of high molecular weight unsaturated fatty acid and alcoholpresent. Proportions in this range are very satisfactory.

The mixture of unsaturated acid and alcohol is reacted with the'maleicacid or maleic anhy- This product is then reacted with an olefin oxideor corresponding glycol such as ethylene.

propylene or butylene oxides or ethylene. propylene or butylene glycols.It is necessary that the olefin oxide or corresponding glycol be of lowmolecular weight, 1. e., less than about eight carbon atoms. The olefinoxideor corresponding glycol is preferably added in amounts of about0.25 to 1 mol of oxide or glycol per mol of alcohol contained in theoriginal high molecular weight alcohol-unsaturated fatty acid mixture.Larger or smaller amounts may be used. The reaction with the olefinoxide or glycol is likewise assisted by heating and is alsoadvantageously carried out in the presence of a solvent. The lycol oroxide is advantageously directly added to the reaction mixturecontaining the maleic acid or anhydride-reaction product.

The product thus prepared contains free carboxylic acid and is thereforesubstantially neutralized with an aliphatic primary amine containingbetween about 8 and 26 carbon atoms."

Normal straight chain primary amines such as decyl'amine and octadecylamine are advantageously used but it is satisfactory to use unsaturatedprimary aliphatic amines such as undecylene amine. Mixtures of straightchain primary alkyl amines such as cocoamine are advantageous because oftheir relative cheapness. Cocoamine is a commercial mixture of higheralkyl amines prepared from cocoanut oil fatty acids. It contains a majoramount of primary dodecyl amine and typical samples thereof have beenfound to have an average molecular weight ranging from 200 to 210.- Theamine is used in an amount such that the reaction prodv ucts will besubstantially neutralized.

in'the'mineral oil lubricating base preferably in amounts of about 0.1to 5 per cent on a solvent free basis., However, larger or smalleramounts may be used to obtain reduction in corrosion,

rusting and foaming properties. It is advantagev 'The'final productcan-be directly incorporated ous to prepare a concentrate of thisproduct in a mineral oil or fraction thereof and use this concentrate asa convenient vehicle for incorporating in the lubricating base.

Example1.-'-Into a closed iron reaction vessel there was charged 500pounds of refined sperm 1' 7 011,700 pounds of a light lubricating oil,and 80 pounds of per cent caustic soda. The tempera;- ture was raised to320 F. for 5 hours, while maintaining 30- pounds of pressure per squareinch dried at 240 F. under 15 inch mercury pressure.

Then the material was cooled to 200 F. after which 50 pounds of maleicanhydride and 38 pounds of propylene glycol were added. The temperaturewas maintained at 200 F. for 6 hours, following which 291 pounds ofcocoaminewere added to neutralize the resulting acidity.- The producthad the following properties:

Gravity: API 28.2 Viscosity, SUV: 210 F 50.1 I Pour: F +50 pH value 7.8Neutralization number 18.0

. 4 Example 2.A highly refined lubricating oil was treated with 0.5 percent by volume of an additive prepared according to Example 1.Comparative tests indicating the properties of the base and inhibitedlubricating oil are:

B... on gg Gravity: API 26.0 25.9 Viscosity SUV F l, 1,17! Flas ,06):F... 420 420 Pour: F +10. +10 Corrosion Test: I ASTM D665-46T- SteelRod: Appearance rust bright Area Rusted: Percent 100 0 Air Bubbling FoamTest:

Method 435, .Guli- Vol. Oil dz Foam: Vol. Oil 77 F... 4. 5 l. 02

Gravity: API 26.0 Viscosity, SUV: 210 F 47.1 Pour: "F +55 pH value 7.9Neutralization number 21.0

Example '4.-A highly reflned turbinc oil was treated with 0.3 per centby weight of an additive prepared according to Example 1. Comparativetests indicating the properties of the base oil and theinhibited-turbine oil are:

- Inhibited Base 011- on Gravity: API 29.4 29.3 Viscosity, SUV:

0 53.0 51.0 Viscosity Index. 100 100 Fla O 450 450 Fire, C: 510 510 our:"F +5 +5 Color, NPA 2. 0 2. 0 Corrosion Test:

ASTM D665-46T- Steel Rod: Appearance rust bright Area Rusted: Per Cent100 0 Air Bubbling Foam Test:

Method 4315. Gulf- Vol. Oil 6: Foam: Vol. 0l177 F... 4. 6 1.02

The compounded lubricant of the present invention has many advantages.Itwill be noted that the corrosion and rusting of metal surfaces isgreatly reduced so that the moving parts of power generating equipmentwould remain-in good condition for a longer period and would: continueto deliver approximately the original power output after many hours ofuse. The conipounded lubricants of the present invention also haveincreased oiliness so that they can be used to eifectively lubricatebearingswhich are operating under high pressures. These productsalsohave greatly reduced foaming characteristics. This is, of course,important since a lubricant which foams to a large extent cannot be usedto lubricate engines operating under extreme conditions. Theseadvantages are notobtained if an acid or anhydride other than maleic isused.

What we claim is: 1. As an improved'eompound lubricant. a uniiorm blendof a mineral oil lubricating base with a small amount, sumcient toretard rust and corrosion, of a product obtained by reacting at atemperature between about room temperature and about 200 F., a mixtureof an unsaturated fatty acid containing 8 or more carbon atoms and analiphatic alcohol containing 8 or more carbon atoms with (one) a memberof the group consisting of maleic acid and-maleic anhydride and (two) amember of the group consisting of olefin oxides containing less thanabout 8 carbon atoms and glycols corresponding thereto and thenneutralizing the reaction product with an aliphatic primary aminecontaining from 8 to 26 carbon atoms.

2. As an improved compound lubricant, a uni- -form blend of a mineraloil lubricating base with between about 0.1 and per cent of a productobtained by reacting at a temperature between about room temperature andabout 200 F., a 20 mixture of an unsaturated fatty acid containing 8 ormore carbon atoms and an aliphatic alcohol containing 8 or more carbonatoms with (one) a member of the group consisting of maleic acid andmaleic anhydride and (two) a member of the group consisting of olefinoxides containing less than about 8 carbon atoms and glycolscorresponding thereto and then neutralizing the reaction .product withan aliphatic primary amine containing from 8 to 26 carbon atoms.

3. As an improved compound lubricant, a uniform blend of a mineral oillubricating base with a small amount, sufliclent to retard rust andcorrosion, of a product obtained by reacting at a temperature betweenabout room temperature and about 200 F., a mixture of an unsaturatedfatty acid containing 8 or more carbon atoms and an aliphatic alcoholcontaining 8 or more carbon atoms with (one) a member of the groupconsisting of maleic acid and maleic anhydride and (two) a glycolcontaining less than about 8 carbon atoms and then neutralizing thereac= tion product with an aliphatic primary amine containing from 8 to26 carbon atoms.

4. As an improved compound lubricant, a uniform blend of a mineral oillubricating base with a small amount, sufllcient to retard rust andcorrosion, of a product obtained by reacting at a temperature betweenabout roomtemperature and about 200 F., a mixture of an unsaturatedfatty acid containing 8 or more carbon atoms and an aliphatic alcoholcontaining 8 or more carbon atoms with (one) a member of the group con-8 slsting oi maleic acid and maleic anhydride and (two) an olefin oxidecontaining less than about 8 carbon atoms and then neutralizing thereaction product with an aliphatic primary amine containing from 8 to 26carbon atoms.

5. As an improved compound lubricant, a uniand glycols correspondingthereto and then neutralizing the reaction product with an aliphaticprimary amine containing from 8 to 26 carbon atoms.

, 6. As an improved compound lubricant, a uniform blend of a mineral oillubricating base with a small amount, sufficient to retard rust andcorrosion, of a product obtained by reacting, at a temperature betweenabout room temperature and about 200 F., the hydrolysis products ofsperm oil with (one) maleic anhydride, and (two) propylene glycol andthen neutralizing the reaction product with an aliphatic primary aminecontaining from 8 to 26 carbon atoms. '7. As an improved compoundlubricant, a uni form blend of a mineral oil lubricating base with asmall amount, suiilcient to retard rust and corrosion, of a productobtained by reacting, at a temperature between. about room temperatureand about 200 F., a mixture of oleic acid and cetyl alcohol with (one)maleic anhydride and (two) ethylene glycol and then neutralizing thereaction product with an aliphatic primary'amine containing from 8 to 26carbon atoms.

. HERSCHEL G. SMITH.

TROY L. CANTRELL. JOHN G. PETERS.

REFERENCES CITED The following referenlces are of record in the file ofthis patent:

UNITED grams PATENTS

